2.3: Activities and Answer Keys

Activity 1-1: Are You What You Eat?

PLAN

Summary Students begin their study of nutrition by keeping a food diary for two consecutive days. They determine the calories (Cal) and compare percentages of fats and proteins in their diets with the recommended guidelines.

Objectives

Students:

record food and beverages they consume for two consecutive days.

calculate their individual and the class average percentages of calories (Cal) available from fats and proteins.

Social Studies Study diet and foods from different parts of the world and from different periods in history.

Design a “Heart Smart” restaurant as an interdisciplinary project. Include invitations, menus giving nutritional information, meal planning, and preparation around a cultural theme.

Math Calculate percents of fats, proteins, and carbohydrates present in various diets.

Home Arts Produce an ethnic food fair.

Prerequisites and Background Information

The recommended guideline of under 30% fat includes both saturated and unsaturated fats. For saturated fats the recommended percent is under 10% of the total calories consumed in a day. The recommended amount of protein for growing bodies is 15% of the total calories consumed in a day.

IMPLEMENT

Instruct students to begin entering food data in the morning, so that each data page will contain one day's record.

Show students how to use the Food Nutrient Chart to find needed information.

Introduce the idea of the calorie (Cal) as a unit of heat energy provided by food.

Step 2 Fill in a sample Food Diary using the overhead projector with students emphasizing where to record the number of calories and grams of fats, protein, and carbohydrates. Remind students that the recommended daily allowance for calories (Cal) can be found in their text on page 18. A complete Recommended Daily Allowances chart is located on page 96 of this book.

Extend Activity 1-1 by using the Activity Report and Diet Data Sheet for assessment at the end of the unit.

Helpful Hints

Special emphasis in this activity is on fats and proteins to create an awareness of diets having too much fat and/or too little protein.

Students keep the food diary for 4 days and choose 2 of the most typical days out of the 4 days.

The Food Nutrient Chart lists many common foods with the number of calories (Cal), and amounts of protein, carbohydrates, and fat contained per serving. Additional resources can be made available for those foods that are not as commonly found in diets in the United States.

When analyzing ethnic foods, students may need assistance. They can list the main ingredients and then look for the more common food ingredients that are similar to the foods on their list.

Display a Food Pyramid for reference.

Provide some examples of serving sizes. Student totals for calories (Cal) consumed often reflect a much lower daily total from what is actually taken in. The examples can be found in Home Economics catalogues. An alternate way to show serving size is to shape pieces of clay into foods. Particularly helpful are models for 3 ounces of chicken or meat, 1 ounce slice of cheese, and cup servings of pasta, rice, and/or vegetables.

A helpful resource that lists many foods is Are You Eating Right? by Dr. Judi Morrill, San Jose State University, San Jose, CA, 95192-0058.

ASSESS

Use the completed Food Diary, Data Sheet, and written responses on the Activity Report to assess if students can

keep an accurate record of all food and drink for 2 days.

calculate the average percentage of calories available from fats and from proteins in the two-day diet.

compare their diets to the guidelines for healthful limits recommended by the American Heart Association.

identify possible health risks associated with unhealthy diets.

Activity 1-1: Are You What You Eat? – Activity Report Answer Key

Sample answers to these questions will be provided upon request. Please send an email to teachers-requests@ck12.org to request sample answers.

Fill in the following chart using your totals from your two-day food diary, Resource 1.

How do the percentages of fats and proteins consumed compare to the recommended (a) 30% or less fat and (b) 15% or more from protein? Explain.

What changes, if any, could you make so that the percentages of Calories from fat consumed would fall within the recommended range of under 30% of the total Calories consumed?

What changes, if any, could you make so that the percentages of Calories from protein consumed would fall within the recommended range of 15% or more of the total Calories consumed?

What are two possible consequences for adolescents of diets too high in fat and too low in protein?

What Do You Think?

Why is it that you see lots of ads for fast food and junk food, but very few ads for vegetables and fruits?

Write an Advertisement Students create an advertisement for a fruit or vegetable designed to make the fruit or vegetable more appealing.

Word Origin of Carbohydrate Students do a library research to find the origin and chemical structure of carbohydrates.

A suggested response will be provided upon request. Please send an email to teachers-requests@ck12.org.

Why do coaches tell their athletes to eat a big pasta dinner the night before a competition and simple sugars a few hours before the competition? Why don't the athletes eat pasta right before the competition and a candy bar the night before?

Vegans are people who don't eat any animal products, including meats, eggs, or dairy products. How can these people still get the protein their cells need to grow if each kind of plant they eat doesn't contain complete proteins?

One brand of granola has a label on the container stating, in big letters, “NO TROPICAL OILS.” Why do you think this has been pointed out?

Considering the list of possible ways to reduce fat in your diet, which three things would be the easiest for you to try as part of your own diet? Which three things would be the hardest for you to try? Why? Do you think it is important for you as an adolescent to monitor the fat in your diet? Why or why not?

Many people take vitamin supplements in the form of pills or vitamin shakes. Now that you know the various vitamins found in foods and what they do for your body functions, what is your personal “philosophy” about getting enough of all the vitamins you need? Do you take large doses of vitamin supplements, moderate amounts, or none at all? Why? How does the information in this section affect your decisions about the vitamins that you consume?

Make a list of all the things that could go wrong with your body due to vitamin A, B, C, and D deficiencies. Which would be the hardest for you to deal with? Are you willing to eat the foods that contain that vitamin to prevent this problem? Why or why not?

What Do You Think?

Why do you think there are so many advertisements for milk featuring famous athletes and movie stars drinking milk? What audience arc these ads targeting? As a consumer, do you think the ads are effective?

A suggested response will be provided upon request. Please send an email to teachers-requests@ck12.org.

What do cooks mean when they say, “A colorful plate is a healthy plate”?

Activity 1-2: What's in Your Food?

PLAN

Summary Students test standard samples of starches, glucose, proteins, and fats to observe and record the chemical reactions. Then they test a variety of food samples to determine the presence, or absence, of carbohydrates, fats, and proteins in each.

Objectives

Students:

perform standard tests to identify carbohydrates, protein, and fat.

determine the presence of glucose, starch, sugar, protein, or fat in a variety of foods.

Cut up foods to be tested and assemble so students can obtain them easily. Make control solutions: 1. Protein: egg whites beaten, 2. Sugar: of corn syrup mixed with of warm water.

Estimated Time One and one-half 50-minute periods

Interdisciplinary Connections

Art Make a poster or a collage grouping pictures of the different food types.

Language Arts Write about the differences between sugars, starches, fats, and proteins, which foods contain them, and how they are needed in your body.

Prerequisites and Background Information

SAFETY: Awareness of fire safety, how to use a burner, and how to handle chemical indicators properly is mandatory, Review the safety rules for working in laboratory situations. Wear goggles to model appropriate laboratory safety.

Review with students how to use a graduated cylinder.

Extend Activity 1-2 by having students test plant leaves for glucose and starch after the leaves have been placed in both light and dark environments.

IMPLEMENT

Carbohydrates-sugar and starch-provide energy for your cells. The long chain carbohydrate molecules are broken down into smaller sugar molecules.

Proteins are digested into building blocks of amino acids. Amino acids are used for building new proteins, which can be used for repairing cells, fighting infections, and other functions including growth.

Fats are large molecules that store energy and can be digested into building blocks called fatty acids. Fats help you absorb vitamins. They also form part of the cell membrane.

Demonstrate or review the safe procedure for heating liquids in a test tube.

Caution students to use care in handling Biuret and iodine solutions. Provide the Data Sheets for Parts A and B (Resources 1 and 2).

Part A Proceed with Part A as either a student activity or a demonstration to test for starches, sugars, proteins, fats, and oil. Demonstrate the standard tests for carbohydrates, proteins, and fats.

Part B Proceed with Part B as either a student activity or a demonstration to test for nutrients.

Helpful Hints

Provide a variety of foods for testing.

Have students compare test results from the foods tested (colors) with the standards.

ASSESS

Use the completion of the experiment and written responses on the Activity Report to assess if students can

determine the presence of glucose, starch, sugar, protein, or fat in given foods.

Activity 1-2: What's in Your Food? – Activity Report Answer Key

Sample answers to these questions will be provided upon request. Please send an email to teachers-requests@ck12.org to request sample answers.

Which of the foods you tested contain

protein?

carbohydrates: sugars? starches?

fats?

Which, if any, of the foods contained all three nutrients (carbohydrates, proteins, and fats)?

Which foods provide quick energy? Why?

Which foods promote growth and cell repair? Why?

Which foods increase the intake of

carbohydrates?

protein?

fats and oils?

What are some ways to limit intake of fats and oils?

Two groups testing a cookie for sugar with the Benedict's solution got different results from the same cookie. One group found that the Benedict's solution in the test tube turned green and the other group found that it turned orange. Give a possible reason for the difference observed.

Activity 1-2: What's in Your Food? – Resource 1 Answer Key

Part A Data Sheet Answer Key

Part A: Laboratory Tests for Nutrients

Nutrient

Description of Test

Results

Carbohydrates (Starch)

Iodine

Iodine changes in color from red to purple-black

Carbohydrates (Sugar)

Benedict's

Benedict's, when heated in the presence of glucose changes in color from blue/green to orange/brown

Protein (Albumin)

Buiret

Buiret, in the presence of protein, changes in color from light blue to pink/violet

Fats and Oils

Brown Bag Paper

Brown bag paper in presence of fat or oil turns clear

Activity 1-2: What's in Your Food? – Resource 2 Answer Key

Part B Data Sheet Answer Key

Part B: Testing Foods for Nutrients

Indicate the results of your tests for nutrients by writing “yes” or “no” in each box.

Food Tested

Carbohydrate (Starch)

Carbohydrate (Sugar)

Protein

Fats and Oils

1. Milk

No

Yes

Yes

Yes

2. Hamburger

No

No

Yes

Yes

3. Potato

Yes

No

No

No

4. Bread

Yes

Yes

Yes

No

5.

6.

7.

8.

9.

10.

Review Questions/Answers

Sample answers to these questions will be provided upon request. Please send an email to teachers-requests@ck12.org to request sample answers.

Why does what you eat matter?

Compare a carbohydrate molecule and a glucose molecule.

What is meant by the terms essential amino acids and complete proteins?

What is the difference between saturated and unsaturated fats?

What are three examples of a vitamin or a mineral deficiency? What disorders can each cause?

What are five body functions that need the recommended five 8-oz glasses of water you should drink every day?